Abstract

In this study, a Ti1.5Nb1Ta0.5Zr1Mo0.5 (TNTZM) high-entropy alloy was fabricated using laser powder bed fusion (LPBF). By integrating 63 sets of parameter trials with machine learning (ML) models, an optimised process window was identified, achieving a density of up to 99.9%. The combination of relatively high laser power and low scanning speed resulted in the formation of a stable cellular structure. Subsequent heat treatments at 700, 850, and 1000°C showed that while small-angle misorientations developed at cell-wall interfaces and medium-entropy (Ti–Zr–Mo) second-phase particles precipitated preferentially in the cell walls, the overall cellular architecture remained intact. Mechanical testing showed that these heat-treated samples exhibited yield strengths over 150 MPa higher than the as-built samples, while still retaining nearly 50% ductility under short-term heat treatment. In particular, small-angle grain boundaries and nanoscale second-phase particles together reinforce the cell walls and promote intracellular dislocation accumulation, thereby improving the overall mechanical properties of the alloy. These results demonstrate that combining ML-guided process design with targeted heat treatment is an effective method for additive manufacturing of refractory HEAs with high density and mechanical properties.

RAS ID

83444

Document Type

Journal Article

Date of Publication

1-1-2025

Volume

20

Issue

1

School

Centre for Advanced Materials and Manufacturing / School of Engineering

Creative Commons License

Creative Commons Attribution-Noncommercial 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial 4.0 License

Publisher

Taylor & Francis

Identifier

Lai Chang Zhang: https://orcid.org/0000-0003-0661-2051

Comments

Jiang, D., Luo, M., Liu, C., Zhang, Y., Zhang, L., Wang, K., Wang, W., Xie, L., Wang, L., Lu, W., & Zhang, D. (2025). 3D Printing parameter optimisation combined with heat treatment for achieving high density and enhanced performance in refractory high-entropy alloys. Virtual and Physical Prototyping, 20(1). https://doi.org/10.1080/17452759.2025.2524524

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